Most modern entertainment systems now include a television converter device, often in the form of a set-top-box (STB), as well as a television (TV). While TVs typically include tuners capable of selecting a channel of television programming from the multitudes of channels broadcasted over the air (typically via an attached TV antenna), STBs have become standard to access and select channels of television programming provided by alternate distribution services such as cable and direct-to-home satellite services.
STBs typically contain some kind of a channel selector, a control means, and typically a separate remote controller, for the user to give instructions to the STB. Channel selectors could take any form, ranging from a simple radio tuner to complex and specially designed hardware and software devices. In simple terms, channel selectors can select any channel of television programming from the multiple channels delivered to the STB by the programming distributor and then deliver that channel of television programming to the TV in a form that the TV is able to recognize and subsequently display (typically via channel 3 or 4 on the TV's tuner or via a separate baseband input). Current industry practice is for a programming distributor to provide each subscriber with one STB (with one channel selector) for each of the subscriber's TVs.
Modern STBs now support a wide array of functions and services that go beyond simple channel selection. It is now common for STBs to also be digital video recorders (DVRs) through the internal or external inclusion of a hard drive or other storage device, along with the associated control hardware and software. Many STBs also allow users to directly order pay-per-view movies from the programming distributor via a modem connected to a telephone line at the subscriber's location. Increasingly, STBs store information related to certain user preferences that increase user friendliness of the service. It has also become important that STBs provide users with some means of blocking undesirable television programming.
The trend in STB design is to include more and more components and functionalities in the STB. There is an economic incentive for this trend, as including an additional component in the STB is cheaper than providing that component as a standalone device. In addition, there is an operational incentive as the STB manufacturer can ensure that an included component will operate correctly with the other included components, thus increasing customer satisfaction with the overall product. Lastly, many consumers find entertainment systems with a large number of standalone components difficult to use.
As the trend has continued, several problems with the typical STB have been identified. One problem with STBs is associated with the recent development of the picture within a picture functionality found on some TVs, sometimes also referred to as picture-on-picture or picture-in-picture (PIP) display. PIP display allows a user to watch to two channels at the same time: typically with one channel shown in a substantially smaller window that overlays the other displayed channel that is shown on the main TV screen. This functionality, however, requires the use of an extra tuner or channel selector for each additional channel to be displayed. The additional channel selectors proportionally increases the cost of the device, be it a TV or STB, even though the second channel selector remains idle most of the time.
Yet another drawback to typical STBs is the inability to perform housekeeping functions, such as downloading system information, software updates, menus, and any content to be stored and displayed later or uploading stored information such as user viewing information and system performance information, while the STB is in use. As STBs have become more complicated, the need for performing such housekeeping functions has drastically increased. Most housekeeping functions, especially those that require the downloading of information embedded in a channel, require the use of a channel selector. However, because modern STBs typically contain a single channel selector, housekeeping functions requiring a channel selector cannot be performed while the channel selector is in use delivering television programming.
Programming distributors currently get around this problem in one or both of two ways. One way is to insert such housekeeping information in every channel of content delivered. Therefore, regardless of whether the channel selector is in use or not, housekeeping information is always available. This is a simple solution but is clearly an inefficient use of bandwidth. Another way is to wait until the STB is turned off to perform housekeeping functions. This, however, means performance of the housekeeping functions must then be dependent upon the user's use habits, which could prevent the functions from being performed in a timely manner. In addition, many users leave their STBs on all the time thereby preventing the performance of such housekeeping functions.
Another problem with modern STBs is referred to as ‘tuner delay.’ It takes all tuners and channel selectors a finite amount of time to “tune” from one channel to another. For example, a satellite STB can take up to two seconds to display a new channel after the receipt of a channel change command, during which time nothing is being delivered to the TV. This tuner delay is perceived by the subscriber and can be the source of much frustration on the subscriber's part. Better quality electronics can be used to reduce tuner delay, but the delay cannot be eliminated. In addition, such better quality electronics are also subject to the law of diminishing returns and they can typically cost much more than a lower quality tuner, for only an incremental decrease in tuner delay.
Programming distributors have also determined that it is now a problem that STBs can only support one TV. Although the additional functions have proved to be very popular with consumers, they have drastically increased the cost and complexity of STBs. For example, the cost of including an internal storage device can substantially increase the manufacturing cost of STBs.